Older than her brother Morgie by ten minutes, Moffie is used to doing everything first. But when Morgie is invited to his first sleepover, Moffie feels like she's being left behind. Morgie is excited, but a little nervous too. What if he misses Moffie? Young children will understand both of the twins' anxieties, and will love finding out what happens during the Big Sleepover.